So you create the registry lights by hand?
Yes and no. In Photoshop, you can make good spotlights by creating another document and going to Render>Lighting Effects. Once opened, you should see 4 sections- Style, Light Type, Properties, and Texture channel (don't use this one, I don't). change the background color in Properties to black, so you won't have a lighter square around your spotlight. Then just move the points composing the spotlight and you are done. Just copy the spotlight into your alpha channel.
Some lights can be done with a blurry brush tool, but not all.